Never stayed at a value, but I would be surprised if they differ too much from the moderates. Maybe one less sink or amenity (e.g., coffee maker). I think the greater difference is in the hotel attributes (e.g., restaurants, bars, pools), and possibly the appeal of the grounds. To answer your question, I would compare the moderate to a Holiday Inn or Courtyard Marriott (except that the doors open to the outside). I'd say three out of five stars. Definitely CLEAN though, which is most important.
Whenever we travel (apart from Disney), we like to stay in four stars or better. But the Disney deluxes are just too pricey for us. So the choice is between a 4-star non-Disney hotel and the moderates. For us, this is a no-brainer - you just can't beat the onsite feeling and benefits. Hope this helps.